Spring clamp connector

Abstract: Actuating means (8) for opening and closing a spring clamp terminal (7) mounted within a connector housing (4) is receivable within a cavity (24) of the housing (4). The actuating means (8) comprises a tapered first camming surface (38) for progressively biasing the spring clamp (7) open, and a second rest surface (40) for maintaining the spring clamp (7) open for reception of a wire (14) without requiring use of the tool (12). Once the wire has been placed in a wire receiving hole (56) of the spring clamp (7), the actuating means (8) can be released by tilting thereof about a pivot line (70) such that the spring arm (54) of the spring clamp (7) engages the first camming surface (38) hence pushing the actuating means outwardly of the cavity (24), thereby enabling clamping of the wire (14).

Description: This invention relates to actuating means for opening an electrical wire spring clamp mounted in a connector housing. In particular, the invention relates to an electrical connector having actuating means as well as to a method of electrically connecting a wire to terminals of a connector. It is well known in the electrical industry, to use spring clamps for connecting electrical wires to an electrical terminal. The spring clamps provide a rapid connection and disconnection system for electrical wires commonly used for example, in large rack and panel connectors whereby the user can easily adapt the wiring to his own needs. The housing and mounting system of such a rack and panel connector could be similar to that described in DE-A-4 410 073. It is known to have an insert receivable in a cavity of a connector for opening a spring clamp by being depressed, whereby a camming surface thereof resiliently biases the spring clamp open for receiving a wire. The problem with this system, is that the insert must be depressed with a screw driver, for example, and be held depressed to maintain the spring clamp open so that the wire can be inserted, the operator thus needing both hands for this operation. The screwdriver also gets in the way and increases the difficulty of placing the wire in the spring clamp hole. It would thus be desirable to provide a spring clamp actuator that maintains the spring clamp in a fully open wire receiving position without requiring any external means therefor and that can be rapidly and simply released such that the wire is clamped to the spring clamp for electrical connection therewith. From document EP 0 052 767 A1 an electrical wire connector has come to be known. This known connector comprises actuating means for opening an electrical wire spring clamp. In a first version of this known connector, the spring clamp is opened and maintained in an open position by a movable ram made in a screw-like form. Another known version uses a wedge for opening and blocking the spring clamp. It is therefore an object of this invention to provide a cost effective and reliable electrical connector having a spring clamp actuator that can be easily manipulated for opening and closing of the spring clamp as well as a related method for electrically connecting a wire to terminals of a connector. It is also an object of this invention to provide an electrical connector having an actuator that can maintain the spring clamp open without requiring external means therefor. These objects are solved according to the invention by an electrical connector exhibiting the features of independent claim 1 as well as by a method of electrically connecting a wire to terminals of a connector exhibiting the features of independent claim 5. Dependent claims 2 to 4 and 6 exhibit further improvements of the subject-matter of the respective independent claim on which they depend. Actuating means are comprising camming means engageable against the spring clamp, the camming means having a first surface for progressively biasing the spring clamp open and a second surface adjacent the first surface for maintaining the spring clamp fully open for receiving the wire without requiring exterior means, the actuating means pivotable whilst in the fully open position such that the spring clamp reengages the first surface thereby enabling the spring clamp to close. The preferred embodiment of this invention will now be described in more detail with reference to the drawing figures whereby; Figure 1 is a cross sectional view through a connector comprising a spring clamp and spring clamp actuator about to be depressed by a screw driver; Figure 2 is similar view to that of Figure 1 but showing the spring clamp actuator in a fully depressed positioned and the spring clamp fully opened and about to receive a electrical conducting wire; Figure 3 is a similar cross sectional view to those above but showing the actuator being tilted in order to release the spring clamp such that it can clamp onto the wire; Figure 4 is a similar cross sectional view to those above but showing the actuator released and the spring clamp clamping the electrical wire. Figures 5 and 6 are, respectively, detailed side and front views of the actuator. With reference to Figure 1 and Figure 2, an electrical connector generally shown at 2 comprises an insulative housing 4, terminals 6 mounted therein, actuating means 8, and a terminal and actuator means cover 10. A screwdriver 12 is also shown for depressing the actuator means 8, and in Figure 2, an electrical conducting wire 14 for electrical conduction to the terminal 6 is shown. The terminal 6 comprises a mating connector contact portion 16 for making electrical contact to terminals of a mating connector, and a spring clamp mounting portion 18 having a bent contacting tab 20 for electrically contacting the wire 14. The housing 4 comprises a terminal receiving cavity 22, an actuator receiving cavity 24 and joining the two, a spring clamp receiving cavity portion 26. The inner cover 10, comprises a wire guide hole 28 having a tapered lead surface 30, the hole aligned above the terminal receiving cavity 22, and an actuator receiving hole 32 above the cavity 24, the actuator hole 32 having shoulders 34 for retaining the actuator 8. The actuator 8 (see Figures 5 and 6) comprises a one piece moulded body having a camming surface 36 comprising a first lower surface 38 for progressive opening of the spring clamp 7 and a second upper surface 40 for maintaining the spring clamp open, a lower back wall support surface 42, an upper back wall tilt surface 44 adjacent the wall 42, an indent 46 at a top end for receiving an exterior tool, and recesses 48 in an upper portion of the actuator 8 forming retention shoulders 50. The spring clamp 7 comprises a clamping portion 52 attached to a resilient spring arm portion 54, the clamping portion 52 comprising a wire receiving hole 56 around the contacting tab 20 of the terminal 6. The construction of the terminal 6 and the spring clamp 7 are well known and will not be described herein in any detail. The spring clamp 7 is a separate part from the terminal 6 and securely mounted thereto. In order to assemble the connector 2, the terminal 6 with the spring clamp 7 is inserted respectively into the cavities 22 and 26 until resilient retention means of the terminal 6 engage with shoulder means of the housing 4. The actuator 8 can then be inserted into the cavity 24 of the housing such that a lower portion 60 of the actuator 8 is wedged between the spring arm 54 of the spring clamp 7 and a side wall 62 of the connector housing 4. The inner cover 10 can then be inserted over the terminal 6 and the actuator 8 until projections 64 of the cover 10 engage in windows 66 of the connector housing 4 for securely fixing the cover 10 thereto. The shoulders of the cover 10 abut against the shoulders 50 of the insert 8 for retention thereof within the housing cavity 24. Connection of the wire 14 to the terminal 6 will know be explained with reference to Figures 1-4. In Figure 1, the actuator 8 is positioned outwardly of the cavity 24 whereby the spring arm 54 is in the fully closed position and rests against the actuator lower portion 60. A tool such as the screwdriver 12 can then be placed in the indent 46 and the actuator depressed therewith such that it is fully inserted into the cavity 24 as seen in Figure 2; whereby the spring arm 54 having an outward bulge portion 68 at an upper end thereof, is progressively resiliently biased by the tapered first camming surface 38 towards the terminal 6. In the fully inserted or open position as shown in Figure 2, the bulge portion 68 of the spring arm 54 is resiliently biased against the second camming surface 40 which is parallel to the connector side wall 62, whereby the actuator lower back wall 42 is pressed against the side wall 62. The tool 12 can thus be removed from the indent 46 as there is no force component tending to push the actuator 8 outwardly of the cavity 24. The intersection between the lower back wall 42 and the slanted upper adjacent wall 44 of the actuator 8 defines a pivot line 70, and the intersection between the first camming surface 38 and the second surface 40 defines a transition line 72, whereby in the fully inserted position, the bulge portion 68 of the spring arm 54 contacts the second surface 40 at the position above the transition line 72 but below the pivot line 70 such that the actuator 8 remains stabily biased against the connector wall 62 without pivoting about the pivot line 70. The wire 14 can thus be inserted into the spring clamp wire receiving hole 56 to a position as shown in Figure 3. In order to clamp the wire to the contacting portion 20 of the terminal 6, the actuator means 8 must thus be lifted out of the cavity 24 in order to allow the spring 54 to bias away from the terminal 6 thus clamping the wire. The latter is done by tilting the actuator about the pivot line 70 such that the lower back wall 42 pivots away from the connector side wall 62. This is achieved by inserting the screwdriver 12, for example, between the actuator and a wall of the inner cover 10, and then twisting the screwdriver such that it pushes on an upper portion 74 of the actuator 8 which is above the pivot line 70. By tilting the actuator, the transition line 72 is rotated past the spring arm bulge portion 68 such that the spring arm bulge portion resiliently biases against the first camming surface 38 as shown in Figure 3. Due to the tapered inclination of the camming surface 38, there is a force component tending to push the actuator 8 outwardly of the cavity 24, the actuator thus moving outwards of the cavity 24 as the spring arm 54 presses against the tapered camming surface 38; and the spring arm 54 biases away from the terminal 6 thus allowing the clamping portion 52 to clamp the wire 14 against the terminal contacting portion 20 as shown in Figure 4. Advantageously therefore, the spring clamp can be open for receiving a wire 14, and maintained in the open position without requiring the use of an external tool by providing the actuator means as described above. The wire 14 can then be clamped to the terminal 6 be merely tilting the actuating means 8 in a rapid and simple manner with the tool 12. The actuating means 8 can be made of a single moulded plastic part with simple geometry and also comprising indent means 46 for assisting positioning of a tool 12 during insertion of the actuating means 8 into the housing cavity 24. The connector 2 can comprise a large number of terminals 6 therein, and the rapid manner in which the actuating means 8 can be depressed thus opening the spring clamp which can be done successively for all of the terminals 6, inserting the wires 14 into the holes 56 and then clamping by merely tilting the actuator 8 saves a considerable amount of time and effort compared to solutions of the prior art.

Claims: Electrical connector, comprising a housing (4), a spring clamp (7) mounted in the housing (4), the housing (4) comprising a cavity (24) receiving an actuating means (8) adjacent the spring clamp (7) for connecting or disconnecting an electrical wire (14) to the spring clamp (7), characterized in that the actuating means (8) is slidably received in the cavity (24) and comprises camming means (36) engageable against the spring clamp (7), having a first surface (38) for progressively biasing the spring clamp (7) open by depressing the actuating means (8) further in the cavity (24) with exterior means (12), and having a second surface (40) adjacent the first surface (38) for maintaining the spring clamp (7) fully open for receiving the wire (14) without requiring the exterior means (12) whereby the spring clamp (7) presses against the second surface (40) and biases the actuating means (8) against a side wall (62) of the cavity (24) thereby maintaining the actuating means (8) in the fully open position, the actuating means (8) pivotable whilst in the fully open position such that the spring clamp (7) reengages the first surface (38) and presses the actuating means (8) outwardly of the cavity (24) thereby enabling the spring clamp (7) to clamp the wire (14). The electrical connector of claim 1 characterized in that the actuating means (8) is comprised of a single moulded part. The electrical connector of claims 1 or 2 characterized in that the actuating means (8) has an indent (46) for positioning the exterior means (12). The electrical connector of any preceding claim characterized in that the actuating means (8) comprises a lower back surface (42), adjacent thereto an upper slanted back surface (44) and a pivot line (70) defined by the intersection therebetween; the lower back wall (42) substantially parallel to the second camming surface (40) and biased against the side wall (62) of the connector housing (4) when the actuating means (8) is in the fully open position, whereby the actuating means (8) is pivotable about the pivot line (70) such that the slanted upper surface (44) rotates towards the connector side wall (62) and the first camming surface (38) engages with the spring clamp (7). A method of electrically connecting a wire (14) to terminals (6) of a connector (2), characterized by the steps of: a) providing a connector assembly comprising a connector housing (4), terminals (6) mounted therein attached to spring clamp connection means (7), actuating means (8) mounted longitudinally slidable along a cavity (24) in the connector housing (4) proximate the spring clamp (7), the actuating means (8) being adapted to be pressed against a wall (62) of the cavity (24) by the spring clamp (7) in its opened position and having a pivot line (70) cooperating with the cavity wall (62) upon actuation of the actuating means (8) whereupon the actuating means (8) is biased outwardly of the cavity (24) by the spring clamp (7); b) depressing the actuating means (8) with exterior means (12) until a fully inserted position; c) removing the exterior means (12) and inserting the wire (14) in the spring clamp (7); d) pivoting the actuating means (8) with exterior means (12) such that the spring clamp (7) is released and thereby the wire (14) is clamped to the terminal (6) for electrical connection therewith. The method of claim 5 characterized by providing the actuating means (8) of any one of claims 1 to 4.

Inventors: KRAEMER RUDOLF, KRAEMER, RUDOLF, Krämer, Rudolf
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1994
Main classification: H01R4
IPC codes: H01R4